The gender pay gap has fallen over the last year but women still earn almost £100 less a week than their male colleagues, according to new figures.

The Office for National Statistics (ONS) said the difference between the hourly pay of men and women working full time, excluding overtime, fell from 10.5% to 9.6%.

Men's average earnings were up 1.4% to £546 a week, while women's rose by 1.9% to £449.

These increases take the average annual wage in the UK to £26,500 - an increase of 1.4% from the previous year.

The statistics appear to contradict research published by the Chartered Management Institute earlier this month which found that female company executives earns more than £400,000 less than a male counterpart over her career.

According to the Institute, the average gender pay gap for UK executives is more than £10,000 annually.

The ONS also found that the difference between the hourly pay of those working full-time and part-time increased - from 57% in 2011 to 59% this year.

The TUC's general secretary Brendan Barber said: "It's encouraging to see the gender pay gap fall again this year but the pay gap between full and part-time workers is actually getting worse.

"This is terrible news for the millions of people who need to work part-time to balance work and caring responsibilities, or who simply can’t find full-time jobs."

He added: "Unless we get to grips with the lack of high quality part-time work we will never tackle in-work poverty."

The statistics also revealed large differences in earnings across different regions in the UK.

Workers in London were the highest paid - with a weekly wage £653 - while those in Wales fared the worst, earning £453 a week.